The invention relates to a system for dosing a substance and creating a foam into a sanitary appliance.
It is well known to provide dispensers for releasing substances, such as bleaches, cleaners or disinfectants gradually or intermittently into toilet bowls. These substances are either dispensed on their own or dispensed together with the water when the toilet is flushed. These substances that are dispensed may be perfumed, colored, or pre-mixed with chemical additives that inhibit staining of the toilet bowl or to discourage microbiological growth.
Dispensers that are predominant in the market are the solid block types. Some of these are placed into the bottom of a tank of a sanitary appliance, where they slowly dissolve and migrate into the tank water by diffusion. Similarly, another type of solid block type of dispenser is adaptable to be held near the rim of the bowl of a sanitary appliance. Mixing occurs when the toilet is flushed, and the flushing water will mix with these blocks to create a solution that is introduced into the bowl. A known problem of these methods of dispensing is that they do not make efficient use of the chemical blocks, and most of the mixed solution is flushed away.
More recent improvements involve the isolation between the substances and the surrounding tank water.
For isolated dispensers, an isolation means is used to separate the chemical solutions from the main tank of water. Generally, air-locks using the concept of U-tubes are used to create this isolation. Examples of this are found in U.S. Pat. Nos. 4,208,747; 4,707,865; 4,305,162; 4,453,278; and 3,778,849. Other types of passive dispensers involve valves that regulate the flow of the solution in response to the water level within the tank. Examples of this type of dispenser are disclosed in U.S. Pat. Nos. 4,491,988 and 4,534,071. However, as these dispensers work in response to the water level within the tank, the solution will be dispensed regardless of whether a user wishes the solution to be dispensed. Again, this results in waste and accelerated depletion of the solution.
The solution dispensed may or may not cause foam. This foam is required to abate the noise and splashes associated with the deposit of solid waste into the bowl of a sanitary system, which can be a source of embarrassment to some.
Foam may be created by the addition of foaming ingredients such as carbonate or bicarbonate and an acid, such as oxalic or citric acid, as well as bonding materials, for example, a gum or high viscosity methylcellulose, and foam stabilizers, for example, saponin or licorice, to the water contained in the toilet bowl. However, these additional chemicals may be hazardous to the environment, and cause potential health effects during accidental human contact.